Wedge, or strike anchors have been long and widely used for securing structural members to concrete, or to secure fixtures into concrete walls or floors. Conventionally, such anchors for concrete or brick and the like, are formed of an outer sleeve having a central bore, of a rigid and preferably hard material, formed so as to be flarable at the end intended to be held within the rigid, hard substrate. The sleeve has an internal bore and an end which can be flared and is either partially flared or has expansion slits extending axially outwardly from the inner end. The bore at the flarable inner end is generally smaller as compared to the remaining threaded bore, extending to the outer end of the sleeve. A slug is firmly positioned within the bore adjacent the expandable inner end, but not permanently attached to the inner walls of the bore. It is intended to be hammered inwardly so as to be movable into the expandable inner end portion, causing it to expand and flare radially outwardly. When the inner end expands, the anchor becomes permanently wedged within the concrete or brick substrate.
Generally, a striking tool is inserted into the bore after the anchor has been inserted into a previously formed hole into the concrete or brick, with a portion extending outside of the bore which is intended to be struck by a hammer or a power tool to force the slug into the expandable portion and, thus, to expand the anchor into a wedge shape that will secure the anchor in the concrete or brick material.
These wedge anchors or expansion anchors are generally secured into a hard surface such as concrete or brick using a mechanical self-wedging effect formed at the inner end of the fastener. Specifically, hammering drives an internal slug against the internally narrower portion of the anchor slot, causing the inner end of the anchor to spread and become wedged in the hole in the concrete or brick.
Previously the setting of the anchor device and wedging into the, e.g., concrete, required a separate hammer and driving tool, to move the slug internally wedged in the channel within the anchor. Such a system requires having available a strike or driving tool having the proper diameter to fit within the anchor bore and to be strong enough to hammer the wedge to flare the inner end of the anchor.